1. Field of the Invention
The present invention relates to a wiring unit and an electric junction box installed in a motor vehicle.
2. Description of the Related Art
Generally, a motor vehicle is equipped with various electronic equipment, namely, lamps such as a head lamp and a tail lamp, and motors such as a starter motor and a motor for an air conditioner.
A junction block is arranged at appropriate points of a motor vehicle in order to supply electric power to the electronic equipment. The junction block is formed by stacking up wiring substrates each having a printed substrate or a busbar and by arranging various and a large number of electric circuit units such as electric relays and fuses.
Here, the junction block may be called fuse block, relay box or electric junction box. In the present specification, a fuse block, a relay box, or a junction block is called an electric junction box hereinafter.
The electric junction box has a casing, a wiring unit 54 (FIG. 7) accommodated in the casing, a waterproof casing, and so on. The casing has a front casing and a back casing. The back casing has a flat bottom wall and a peripheral wall extending from the periphery of the bottom wall. Wires connected with the above electronic equipment are led into the back casing.
The front casing is formed tabularly and arranged opposite the above back casing, while having a gap against the bottom wall of the back casing. Mounting portions for mounting relays, fuses, connectors, and so on are provided on the front casing. The waterproof casing is attachable to and detachable from the rim portion of the peripheral wall of the back casing and, when attached, covers the front casing with the aid of the back casing.
The wiring unit 54 of FIG. 7 is arranged between the front casing and the back casing and is accommodated in the back casing. The wiring unit 54 electrically connects the wires led into the back casing to the relay, fuse, connector, and so on arranged on the front casing according to a given pattern.
The above wiring unit 54 has stacked substrates 61, terminals 62 and connection pins 63. The substrate 61 is made of insulative material and is formed in a generally rectangular plate.
The substrate 61 has a plurality of grooves 64, recesses 65 and through holes 66. The grooves 64 extend in parallel in a longitudinal direction of the substrate 61. The recesses 65 open in one groove 64 and are lined up in a longitudinal direction of the groove 64.
The through holes 66 are bored through respective bottoms of the recesses 65. The substrates 61 have the same arrangement of the through holes 66.
The terminal 62 is made of conductive metal plate and has a pin fitting portion 67 and a wire pressure welding portion 68 as shown in FIG. 8. The pin fitting portion 67 can receive the above connection pin 63.
The wire pressure welding portion 68 defined a direction of the wire 69 (FIG. 7). The wire pressure welding portion 68 has a pair of pressure welding portions 70 to pressure-welded the wire 69 and a pair of wire holding portions 71.
The pressure welding portion 70 has pressure welding pieces 72 which cut the sheathing portion of the wire 69 and get in contact with the core wire. The wire holding portion 71 has a pair of nipping pieces 73 to nip the above wire 69. The nipping pieces 73 put the wire 69 therebetween.
The pin fitting portion 67 is arranged relatively to the wire pressure welding portion 68 in order not to hinder the wire 69 from being arranged as shown in FIG. 8.
The terminal 62 electrically connects the connection pin 63 inserted into the pin fitting portion 67 to the wire 69 pressure-welded to the wire pressure welding portion 68. And, the terminal 62 is attached to the above substrate 61 in a state that the above pin fitting portion 67 is accommodated in the recess 65 and the wire pressure welding portion 68 is accommodated in the groove 64.
The connection pin 63 is made of conductive material in a strip-like shape. The connection pin 63 is electrically connected to the above wire 69 when inserted into the pin fitting portion 67 of the terminal 62 through the above through hole 66.
The wires 69 connected to various electronic equipment are arranged in the grooves 64 of the wiring unit 54, while arbitrarily selecting the recesses 65 and the through holes 66 according to a given pattern, and are electrically connected to the relay, fuse, connector, and so on which are mounted on the mounting portions of the above front casing.
With respect to the above prior art wiring unit 54, however, since the grooves 64 and the recesses 65 are formed on the substrate 61, the shape of the substrate 61 becomes relatively complicated, thereby making the molding pattern complicated and therefore increasing the cost. And, since the terminal 62 is formed by bend a metal plate at a lot of points, the work needs much man-hour, thereby increasing the cost. Further, since the recesses 65 are formed beside the groove 64, the width of the substrate 61 become large, thereby large-sizing the wiring unit 54.
In view of the foregoing, an object of the present invention is to provided a wiring unit and an electric junction box enabling downsizing and cost reduction.
In order to achieve the above object, as a first aspect of the present invention, a wiring unit comprises: insulative substrates, each having through holes, to be stacked up each other; strip conductors, each having contact holes meeting the respective through holes, to be arranged in parallel on each of the insulative substrate; and a conductor pin consisting of a pin portion of conductive material to be inserted into both the through hole and the contact hole with a gap therewith and a conductor contact portion radially projecting from the pin portion so as to be put into contact with the strip conductor.
As a second aspect of the present invention, based on the first aspect, the conductor contact portion has a peripheral portion, being elestically deformable in a radial direction of the pin portion, to be put into contact with the strip conductor.
As a third aspect of the present invention, based on the first or second aspect, at least one of the strip conductors has a male tab to protrude from an end portion of one of the insulative substrates so as to be connected with a terminal electrically connected with external equipment.
As a fourth aspect of the present invention, an electric junction box comprises: insulative substrates, each having through holes, to be stacked up each other; strip conductors, each having contact holes meeting the respective through holes, to be arranged in parallel on each of the insulative substrate; a conductor pin consisting of a pin portion of conductive material to be inserted into both the through hole and the contact hole with a gap therewith and a conductor contact portion radially projecting from the pin portion so as to be put into contact with the strip conductor; and a male tab, provided on at least one of the strip conductors, to protrude from an end portion of one of the insulative substrates; and a connector unit consisting of a wire, a terminal connected with the wire, and a housing accommodating the terminal, the terminal being connected to the male tab.
According to the above-described structures of the present invention, the following advantages are provided.
(1) Because an electric connection, in accordance with a predetermined pattern, between the strip conductors can be attained by arbitrarily selecting the through hole, to which the conductor pin is inserted, of the insulative substrate and the contact hole of the strip conductor, manufacture man-hour can be reduced. And, because the molding pattern of the substrate is relatively simple, its cost can be reduced. And, because the contact hole is provided on the strip conductor itself, the deviation of the contact hole from the strip conductor does not occur and also the width of the insulative substrate can be reduced, thereby attaining the downsizing.
(2) Because the conductor pin is securely electrically connected with the strip conductor, the strip conductors can be securely electrically connected with each other even according to an arbitrarily predetermined pattern.
(3) Because the terminals electrically connected with external equipment can be connected to the male tabs of the strip conductors provided at the end portion of at least one of the insulative substrates, the external equipment and the strip conductors can be electrically connected with each other according to a desirable pattern.
(4) Because an electric connection, in accordance with a predetermined pattern, between the strip conductors can be attained by arbitrarily selecting the through hole, to which the conductor pin is inserted, of the insulative substrate and the contact hole of the strip conductor, and because the terminals of the connector unit electrically connected with external equipment can be connected to the male tabs of the strip conductors provided at the end portion of at least one of the insulative substrates, the fellow strip conductors or the external equipment and the strip conductors can be electrically connected with each other according to a desirable pattern, manufacture man-hour can be reduced. And, because the molding pattern of the substrate is relatively simple, its cost can be reduced. And, because the contact hole is provided on the strip conductor itself, the deviation of the contact hole from the strip conductor does not occur and also the width of the insulative substrate can be reduced, thereby attaining the downsizing. Further, because the terminals of the connector unit connected with the external equipment can be connected to the male tabs, the thickness of the electric junction box can be reduced, thereby downsizing the electric junction box.